Surface modification of electron transport layers based on TiO₂ nanorod boosts efficiency of perovskite solar cells

Abstract

In this work, TiO 2 heterostructure thin films including rutile TiO 2 nanorods (TNRs) and anatase TiO 2 nanoparticles (TNPs) on fluorine-doped tin oxide (FTO) glass are fabricated by the hydrothermal method and are applied as electron transport layers (ETLs) in MAPbI 3 -based perovskite solar cells (PSCs). To enhance the surface area of ETL, TNRs are first etched in acidic solution by another hydrothermal process for different reaction times before coating with TNPs. The morphological and structural properties of TNRs after etching are carefully investigated. Interestingly, the surface modification of TNR thin film by appropriate TNP deposition and etching improves significantly the efficiency of PSC devices by more than 1.6 times. To further improve the performance of PSC, phenyl-C61-butyric acid methyl ester (PCBM) is used to enhance the charge transfer efficiency at the ETL/perovskite interface, and the optimal PSC device shows the champion efficiency of 18.50% with low charge transfer resistance (11.56 ohms).

Metal-Doped TiO2 Thin Film as an Electron Transfer Layer for Perovskite Solar Cells: A Review

“…Thus, the interface between TiO2 and perovskite retards the photoresponse of the resultant devices and leads to strong hysteresis [60]. Extensive research has been conducted to improve the bulk properties of TiO2 ETLs, thus producing long-term stability of PSCs that include elemental doping [61,62], morphological control [63][64][65], and surface modification [66][67][68][69]. Surface modification is one way to produce a good-quality ETL by modulating the interface energetics and improving the physical contact between the ETL and the perovskite layer [70].…”

Interfacial Engineering of a TiO2 Photoanode via Graphene Nanoribbons for Efficient Quantum-Dot-Sensitized Solar Cells and Photoelectrochemical Water Splitting

“…Moreover, to improve the electron transport through the photoanode, one-dimensional (1D) nanostructures with fewer grain boundaries and a highly conducting charge transport network are generally employed alongside m-TiO 2 . Until now, various 1D nanostructures, such as nanofibers, nanowires, , and nanorods, , have been doped in the m-TiO 2 -based photoanode to enhance the charge transport. Nowadays, 1D carbonaceous materials are a prominent choice as dopants in m-TiO 2 photoanodes as a result of their highly conductive nature.…”